 /* crypto/bn/bn_word.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 * 

 * This library is free for commercial and non-commercial use as CrLONG32 as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 * 

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from 

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 * 

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * 

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */



#include "crypto/CrBNConfig.h"

#ifdef _BN_WORD_C



//#include <stdio.h>

#include "crypto/CrBN.h"

#include "crypto/CrBNLcl.h"







BN_ULONG

BN_mod_word(BIGNUM* a, CrULONG32 w)

{



#ifndef BN_LLONG

	BN_ULONG ret=0;

#else

	BN_ULLONG ret=0;

#endif

	CrINT32 i;



	w&=BN_MASK2;



	for (i=a->top-1; i>=0; i--)

	{

#ifndef BN_LLONG

		ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(CrULONG32)w;

		ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(CrULONG32)w;

#else

		ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%

			(BN_ULLONG)w);

#endif

	}



	return((BN_ULONG)ret);

}



BN_ULONG

BN_div_word(BIGNUM* a, CrULONG32 w)

{

	BN_ULONG ret;

	CrINT32 i;



	if (a->top == 0)

		return(0);

	

	ret=0;

	w&=BN_MASK2;

	

	for (i=a->top-1; i>=0; i--)

	{

		BN_ULONG l,d;

		

		l=a->d[i];

		d=bn_div64(ret,l,w);

		ret=(l-((d*w)&BN_MASK2))&BN_MASK2;

		a->d[i]=d;

	}

	

	if (a->d[a->top-1] == 0)

		a->top--;

	

	return(ret);

}



CrINT32

BN_add_word(BIGNUM* a, CrULONG32 w)

{

	BN_ULONG l;

	CrINT32 i;



	if (a->neg)

	{

		a->neg=0;

		i=BN_sub_word(a,w);

		if (!BN_is_zero(a))

			a->neg=1;

		return(i);

	}



	w&=BN_MASK2;



	if (bn_wexpand(a,a->top+1) == NULL)

		return(0);



	i=0;



	for (;;)

	{

		l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;

		a->d[i]=l;

		if (w > l)

			w=1;

		else

			break;

		i++;

	}



	if (i >= a->top)

		a->top++;



	return(1);

}



CrINT32

BN_sub_word(BIGNUM* a, CrULONG32 w)

{

	CrINT32 i;



	if (a->neg)

	{

		a->neg=0;

		i=BN_add_word(a,w);

		a->neg=1;

		return(i);

	}



	w&=BN_MASK2;



	if ((a->top == 1) && (a->d[0] < w))

	{

		a->d[0]=w-a->d[0];

		a->neg=1;

		return(1);

	}



	i=0;



	for (;;)

	{

		if (a->d[i] >= w)

		{

			a->d[i]-=w;

			break;

		}

		else

		{

			a->d[i]=(a->d[i]-w)&BN_MASK2;

			i++;

			w=1;

		}

	}



	if ((a->d[i] == 0) && (i == (a->top-1)))

		a->top--;



	return(1);

}



CrINT32

BN_mul_word(BIGNUM* a, CrULONG32 w)

{

	BN_ULONG ll;



	w&=BN_MASK2;

	if (a->top)

	{

		ll=bn_mul_words(a->d,a->d,a->top,w);

		if (ll)

		{

			if (bn_wexpand(a,a->top+1) == NULL)

				return(0);

			a->d[a->top++]=ll;

		}

	}



	return(0);

}



#endif //end of #ifdef _BN_WORD_C


